Rock-drill.



J. A. THOMPSON E. M. MACKIE.

BOOK DRILL.

APPLICATION FILED Nov. z2, 1906.

1,065,007. Patented June 17, 1913.

tool or drill carried thereby.

narran sra'rns PATENT ernten.

JAMES A. THOMPSON AND EDWIN M. MACKIE, OF CHICAGO, ILLINOIS, ASSIGNORS T0 CHICAGO PNEUMATIC TOOL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION 0F NEW JERSEY.

noon-DRILL.

Patented June 17, 1913.

Application tiled November 22, 1906. Serial No. 344,568.

To all 'whom t may concern'.-

Be it known that we, JAMES A. THOMPSON and EDWIN M. MACKIE, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in lRock-Drills, of which the following is. a

'utility of our improved construction of rock drill will be apparent from the description hereinafter given.

In the drawings, Figure 1 is a central longitudinal section of a rock drill embodying our invention; Fig. 2 a plan view of the rear end thereof; Fig. 3 a section on the line 3-3 of Fig. 1 but made on a larger scale, and Fig. 4 a perspective of one of the ratchet pawls.

Inasmuch as our invention concerns only certain parts of features of a rock drill, only those parts of the drill which are more or less particularly concerned in the explanation of the parts or features constituting our invention will be described. Therefore in referring to the old parts it will be sufficient to say that the cylinder 1 is provided with the usual piston 2, tappet-actuated rocker 3 and distributing valve 4 which is operated by such rocker and which controls admission and exhaust of iuid pressureto' and from opposite ends of the cylinder for the proper treciprocation of the piston and the working The rifle or rotating bar 5 is associated and coperates with the piston in the usual and well-known manner, but new and improved ratchet mechanism is provided therefor.

As clearly indicated in Fig. 1, the rotating bar is provided with a ratchet 6 which may be integral therewith or formed separately and securely fixed theretoras may be desired, such bar being ext-ended on its outer end 7 to provide a bearing in the pressure plate 8. Coperating with the ratchet 6 is a series of pavvlsl 9 which are made of the Apeculiar shape shown in Figs. 4 and 5 for a purpose hereinafter made apparent. Each pawl .has a fiatrectangular portion 9a which directly coperates with the ratchet and also a tubular portion 9b along one of its longitudinal edges. This tubular portion of each ratchet forms the bearing portion thereof and the same is arranged to be slipped in sidewise into a socket corresponding thereto in the inner surf'aeaof a ring- 10, which willvbe hereinafter referred to as a slip ring owing to its capability of slipping under certain conditions as hereinafter explained. This slip ring fits within the outer end of the cylinder 1 and surrounds the ratchet portion of the rotating bar. Each pawl is provided with a suitable spring such as spring 11 for the purpose of holding the same inwardly toward the ratchet with a yielding pressure so asto engage the ratchet teeth and prevent backward rotation of the rotating'bar.'

In the present instance each spring 11 is provided with two leaves or portions coiledy around a pin 12 in the slip ring, one leaf pressing against one side of the flat portion of its pawl and the other leaf pressing against the inner surface of t-he slip ring, all as clearly indicated in Fig. 3. By reason of the peculiar shape of theratchet and the bearing therefor, the same are reversible with the result that when one side of a pawl becomes worn outin service by the continual contact of the ratchet teeth, the same may be slipped out sidewise from the ring and then reversed and put back into place so as to present a new surface to the ratchet.

In order to take the end thrust of the slip ring we interpose between such ring and a shoulder 1a of the cylinder a thrust ring 13 which also forms a bearing for the soV rotating bar at a point on the inner side of the ratchet. For applying the proper pressure to the slip ring pressure is applied to the plate 8 by screwing up the nuts 14 on the ends of the side rods 1'5 which causes the pressure to be transmitted to the plate 8 through the medium of the retaining bar 16 and the compression springs 17 The slip ring is therefore set or adjusted to resist a certain amount 0f pressure but it is arranged to slip when such predetermined pressure is reached or exceeded with the result that slippage will occur and breakagewill -be prevented. The pressure plate 8 is provlded with'a lubricating opening for lubricating the bearing at the outer end of the rotating bar which opening is 4closed by a screw lu 18. I, Ve claim:

1. In a rock drill, the combination, with the cylinder and the piston thereof, of a central rotating bar coperating with the piston andhaving ratchets at its outer end, a ring arranged concentric of the bar adjacent the ratchets thereof, said ring having an internal circumferential groove and transverse bearin sockets, and a 'series of springpresse pawls having bearing portions received by the sockets.

2. In a rock drill, the combination, with thecylinder and the piston thereof, of a central rotatin bar coperating with the piston and having ratchets at its outer end, a ring arranged concentric of the bar adjacent the ratchets thereof, said ring having an internal circumferential groove yan transverse bearing sockets, a series of reversible pawls having bearing portions re.- ceived by the sockets, and springs located in said groove and bearing against the pawls.

3. In a rock drill, the combination, with the cylinder and the piston thereof, of a central rotating bar cooperating with the piston, and ratchet and pawl mechanism c0- operating with the bar and comprising a ring fitted to slip within one end of the cylinder and havlng a series of oscillating pawls having bearin portions received by said sockets and a apted to engage the ratchet teeth, and means for applying a predetermined degree of springl pressure to the ring to normally prevent sipping thereof.

4, In a rock drill, the combination, with the cylinder and thepiston thereof, of a central rotating bar coperating with the piston, ratchet and pawl mechanism cooperating with the bar and comprising a rin fitted to slip within one end of the cylinder and arranged concentric of the bar, ratchets on the bar within the ring, a series of pawls bearing within the ring and cooperating With the ratchets, an end head received within the outer end of the cylinder and bearing against the outer face of the ring, and means for applying spring pressure to said head.

5. In a rock drill, the combination, with the cylinder and the piston thereof, of a. central rotating bar cooperating with the piston, ratchet and pawl mechanism cooperating with the bar and comprising a ring iitted to slip Within one end of the cylinder and arranged concentric of the bar, ratchets on the bar Within the ring, a series of pawls bearing Within the ring and cooperating with the ratchets, an end head 8 fitting Within the outer end of the cylinder and bearing against the ring, bolts 15 connected with the cylinder, a cross bar 16, springs 17 strung on the bolts and interposed between *the cross bar and the head,

and nuts 14 on the end of the bolts.

JAMES A. THOMPSON. EDWIN M. MACKIE.

Witnesses:

ELMA A. KENEL, PERoIvAL F. DoYLE. 

